<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This file documents the GNU Assembler "as".

Copyright (C) 1991-2016 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts.  A copy of the license is included in the
section entitled "GNU Free Documentation License".
 -->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Using as: Sparc-Size-Translations</title>

<meta name="description" content="Using as: Sparc-Size-Translations">
<meta name="keywords" content="Using as: Sparc-Size-Translations">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Sparc_002dSyntax.html#Sparc_002dSyntax" rel="up" title="Sparc-Syntax">
<link href="Sparc_002dFloat.html#Sparc_002dFloat" rel="next" title="Sparc-Float">
<link href="Sparc_002dRelocs.html#Sparc_002dRelocs" rel="prev" title="Sparc-Relocs">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Sparc_002dSize_002dTranslations"></a>
<div class="header">
<p>
Previous: <a href="Sparc_002dRelocs.html#Sparc_002dRelocs" accesskey="p" rel="prev">Sparc-Relocs</a>, Up: <a href="Sparc_002dSyntax.html#Sparc_002dSyntax" accesskey="u" rel="up">Sparc-Syntax</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Size-Translations"></a>
<h4 class="subsubsection">9.42.3.5 Size Translations</h4>
<a name="index-Sparc-size-translations"></a>
<a name="index-size_002c-translations_002c-Sparc"></a>

<p>Often it is desirable to write code in an operand size agnostic
manner.  <code>as</code> provides support for this via
operand size opcode translations.  Translations are supported
for loads, stores, shifts, compare-and-swap atomics, and the
&lsquo;<samp>clr</samp>&rsquo; synthetic instruction.
</p>
<p>If generating 32-bit code, <code>as</code> will generate the
32-bit opcode.  Whereas if 64-bit code is being generated,
the 64-bit opcode will be emitted.  For example <code>ldn</code>
will be transformed into <code>ld</code> for 32-bit code and
<code>ldx</code> for 64-bit code.
</p>
<p>Here is an example meant to demonstrate all the supported
opcode translations:
</p>
<div class="example">
<pre class="example">ldn   [%o0], %o1
ldna  [%o0] %asi, %o2
stn   %o1, [%o0]
stna  %o2, [%o0] %asi
slln  %o3, 3, %o3
srln  %o4, 8, %o4
sran  %o5, 12, %o5
casn  [%o0], %o1, %o2
casna [%o0] %asi, %o1, %o2
clrn  %g1
</pre></div>

<p>In 32-bit mode <code>as</code> will emit:
</p>
<div class="example">
<pre class="example">ld   [%o0], %o1
lda  [%o0] %asi, %o2
st   %o1, [%o0]
sta  %o2, [%o0] %asi
sll  %o3, 3, %o3
srl  %o4, 8, %o4
sra  %o5, 12, %o5
cas  [%o0], %o1, %o2
casa [%o0] %asi, %o1, %o2
clr  %g1
</pre></div>

<p>And in 64-bit mode <code>as</code> will emit:
</p>
<div class="example">
<pre class="example">ldx   [%o0], %o1
ldxa  [%o0] %asi, %o2
stx   %o1, [%o0]
stxa  %o2, [%o0] %asi
sllx  %o3, 3, %o3
srlx  %o4, 8, %o4
srax  %o5, 12, %o5
casx  [%o0], %o1, %o2
casxa [%o0] %asi, %o1, %o2
clrx  %g1
</pre></div>

<p>Finally, the &lsquo;<samp>.nword</samp>&rsquo; translating directive is supported
as well.  It is documented in the section on Sparc machine
directives.
</p>



</body>
</html>
